Special Conditions: Learjet Inc., Model LJ-200-1A10 Airplane; Use of Automatic Power Reserve (APR), an Automatic Takeoff Thrust Control System (ATTCS), for Go-Around Performance Credit, 14155-14158 [2013-05006]

Agencies

• Federal Aviation Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 78, Number 43 (Tuesday, March 5, 2013)]
[Rules and Regulations]
[Pages 14155-14158]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-05006]



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Federal Register / Vol. 78, No. 43 / Tuesday, March 5, 2013 / Rules 
and Regulations

[[Page 14155]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2013-0154; Special Conditions No. 25-484-SC]


Special Conditions: Learjet Inc., Model LJ-200-1A10 Airplane; Use 
of Automatic Power Reserve (APR), an Automatic Takeoff Thrust Control 
System (ATTCS), for Go-Around Performance Credit

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for the Learjet Model LJ-
200-1A10 airplane. This airplane will have novel or unusual design 
features associated with utilizing go-around performance credit when 
using an automatic takeoff thrust control system. The applicable 
airworthiness regulations do not contain adequate or appropriate safety 
standards for this design feature. These special conditions contain the 
additional safety standards that the Administrator considers necessary 
to establish a level of safety equivalent to that established by the 
existing airworthiness standards.

DATES: The effective date of these special conditions is February 13, 
2013. We must receive your comments by April 19, 2013.

ADDRESSES: Send comments identified by docket number FAA-2013-0154 
using any of the following methods:
     Federal eRegulations Portal: Go to https://www.regulations.gov/ and follow the online instructions for sending 
your comments electronically.
     Mail: Send comments to Docket Operations, M-30, U.S. 
Department of Transportation (DOT), 1200 New Jersey Avenue SE., Room 
W12-140, West Building Ground Floor, Washington, DC 20590-0001.
     Hand Delivery or Courier: Take comments to Docket 
Operations in Room W12-140 of the West Building Ground Floor at 1200 
New Jersey Avenue SE., Washington, DC, between 8 a.m. and 5 p.m., 
Monday through Friday, except federal holidays.
     Fax: Fax comments to Docket Operations at 202-493-2251.
    Privacy: The FAA will post all comments it receives, without 
change, to https://www.regulations.gov/, including any personal 
information the commenter provides. Using the search function of the 
docket Web site, anyone can find and read the electronic form of all 
comments received into any FAA docket, including the name of the 
individual sending the comment (or signing the comment for an 
association, business, labor union, etc.). DOT's complete Privacy Act 
Statement can be found in the Federal Register published on April 11, 
2000 (65 FR 19477-19478), as well as at https://DocketsInfo.dot.gov/.
    Docket: Background documents or comments received may be read at 
https://www.regulations.gov/ at any time. Follow the online instructions 
for accessing the docket or go to the Docket Operations in Room W12-140 
of the West Building Ground Floor at 1200 New Jersey Avenue SE., 
Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, 
except federal holidays.

FOR FURTHER INFORMATION CONTACT: Doug Bryant, FAA, Propulsion/
Mechanical Systems, ANM-112, Transport Airplane Directorate, Aircraft 
Certification Service, 1601 Lind Avenue SW., Renton, Washington 98057-
3356; telephone 425-227-2384; facsimile 425-227-1320.

SUPPLEMENTARY INFORMATION: The FAA has determined that notice of, and 
opportunity for prior public comment on, these special conditions are 
impracticable because these procedures would significantly delay 
issuance of the design approval and thus delivery of the affected 
aircraft. In addition, the substance of these special conditions has 
been subject to the public comment process in several prior instances 
with no substantive comments received. The FAA therefore finds that 
good cause exists for making these special conditions effective upon 
issuance.

Comments Invited

    We invite interested people to take part in this rulemaking by 
sending written comments, data, or views. The most helpful comments 
reference a specific portion of the special conditions, explain the 
reason for any recommended change, and include supporting data.
    We will consider all comments we receive on or before the closing 
date for comments. We may change these special conditions based on the 
comments we receive.

Background

    On February 9, 2009, Learjet Inc. applied for a type certificate 
for their new Model LJ-200-1A10 airplane (hereafter referred to as the 
``Model LJ-200''). The Model LJ-200 is a business class aircraft 
powered by two high-bypass turbine engines with an estimated maximum 
takeoff weight of 35,550 pounds and an interior configuration for up to 
10 passengers.
    The Model LJ-200 includes an automatic takeoff thrust control 
system (ATTCS) described as an automatic power reserve (APR) system. 
Learjet has requested approval to use the APR as the performance level 
in showing compliance with the approach climb requirements of Title 14, 
Code of Federal Regulations (14 CFR) 25.121(d). Part 25 appendix I 
limits the application of performance credit for ATTCS to takeoff only. 
Since the airworthiness regulations do not contain appropriate safety 
standards for approach climb performance using ATTCS, special 
conditions are required to ensure a level of safety equivalent to that 
established in the regulations.

Type Certification Basis

    Under the provisions of Sec.  21.17, Learjet Inc. must show that 
the Model LJ-200 meets the applicable provisions of part 25, as amended 
by Amendments 25-1 through 25-127 thereto, and part 26, as amended by 
Amendment 26-1 through 26-2 thereto.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 25) do not contain adequate or 
appropriate safety standards for the Model LJ-200 because of a novel or 
unusual design feature, special conditions are prescribed under the 
provisions of Sec.  21.16.

[[Page 14156]]

    Special conditions are initially applicable to the model for which 
they are issued. Should the type certificate for that model be amended 
later to include any other model that incorporates the same or similar 
novel or unusual design feature, the special conditions would also 
apply to the other model under Sec.  21.101.
    In addition to the applicable airworthiness regulations and special 
conditions, the Model LJ-200 must comply with the fuel vent and exhaust 
emission requirements of 14 CFR part 34 and the noise certification 
requirements of 14 CFR part 36, and the FAA must issue a finding of 
regulatory adequacy under Sec.  611 of Public Law 92-574, the ``Noise 
Control Act of 1972.''
    The FAA issues special conditions, as defined in 14 CFR 11.19, in 
accordance with Sec.  11.38, and they become part of the type 
certification basis under Sec.  21.17(a)(2).

Novel or Unusual Design Features

    The Model LJ-200 will incorporate the following novel or unusual 
design features: An automatic takeoff thrust control system (ATTCS) 
described as an automatic power reserve (APR) system that is available 
at all times without any additional action from the pilot. This applies 
during takeoff and go-around flight operations. The aircraft 
performance data is based on the availability of the uptrim power 
during takeoff and approach climb. This results in a novel or unusual 
design feature for which the applicable airworthiness regulations do 
not contain adequate or appropriate safety standards. Therefore, 
special conditions are required that provide the level of safety 
equivalent to that established by the regulations.

Discussion

    Learjet Inc. is proposing to use the APR function of the Model LJ-
200 during go-around and is requesting approach climb performance 
credit for the use of the additional power provided by the APR uptrim. 
The Model LJ-200 powerplant control system comprises a full authority 
digital electronic control (FADEC) for the Pratt & Whitney Canada Model 
PW307B engine. The engine FADEC system includes the APR feature. The 
configuration provides for APR activation during go-around.
    The APR system is available at all times without any additional 
action from the pilot. This applies during takeoff and go-around flight 
operations. The aircraft performance data is based on the availability 
of the uptrim power during takeoff and approach climb.
    The part 25 standards for ATTCS, contained in Sec.  25.904 and 
appendix I to part 25 specifically restrict performance credit for 
ATTCS to takeoff only. Expanding the scope of the standards to include 
other phases of flight, including go-around, was considered at the time 
the standards were issued. However, flightcrew workload issues in the 
event of an engine failure during a critical point in the approach, 
landing, or go-around operations precluded further consideration.
    The ATTCS incorporated on the Model LJ-200 allows the pilot to use 
the same power setting procedure during a go-around regardless of 
whether or not an engine fails. Since the ATTCS is always armed, it 
will function automatically following an engine failure and advance the 
remaining engine to the APR power level. This satisfactorily addresses 
the flightcrew workload issues that were a concern when the ATTCS 
standards were originally promulgated.
    Since the airworthiness regulations do not contain appropriate 
safety standards to allow approach climb performance credit for ATTCS, 
special conditions are required to ensure a level of safety equivalent 
to that established in the regulations. The definition of a critical 
time interval for the approach climb case, during which time it must be 
extremely improbable to violate a flight path based on the Sec.  
25.121(d) gradient requirement, is of primary importance. In the event 
of a simultaneous failure of an engine and the APR function, falling 
below the minimum flight path defined by the 2.5 degree approach, 
decision height, and climb gradient required by Sec.  25.121(d) must be 
shown to be an extremely improbable event during this critical time 
interval. The Sec.  25.121(d) gradient requirement implies a minimum 
one-engine-inoperative flight path capability with the airplane in the 
approach configuration. The engine may have been inoperative before 
initiating the go-around, or it may become inoperative during the go-
around. The definition of the critical time interval must consider both 
possibilities.
    For approval to use the power provided by the ATTCS to determine 
the approach climb performance limitations, the Model LJ-200 must 
comply with the requirements of Sec.  25.904 and appendix I to part 25, 
including the following special conditions pertaining to the go-around 
phase of flight.

Applicability

    As discussed above, these special conditions are applicable to the 
Model LJ-200-1A10. Should Learjet Inc. apply at a later date for a 
change to the type certificate to include another model incorporating 
the same novel or unusual design feature, these special conditions 
would apply to that model as well.

Conclusion

    This action affects only certain novel or unusual design features 
on one model of airplanes. It is not a rule of general applicability.
    The substance of these special conditions has been subjected to the 
notice and comment period in several prior instances and has been 
derived without substantive change from those previously issued. It is 
unlikely that prior public comment would result in a significant change 
from the substance contained herein. Therefore, the FAA has determined 
that prior public notice and comment are unnecessary and impracticable, 
and good cause exists for adopting these special conditions upon 
issuance. The FAA is requesting comments to allow interested persons to 
submit views that may not have been submitted in response to the prior 
opportunities for comment described above.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.
    The authority citation for these special conditions is as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701, 44702, 44704.

The Special Conditions

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the following special conditions are issued as part of 
the type certification basis for Learjet Model LJ-200-1A10 airplanes.
    1. General. An automatic takeoff thrust control system (ATTCS) is 
defined as the entire automatic system, including all devices, both 
mechanical and electrical, that sense engine failure, transmit signals, 
actuate fuel controls or power levers, or increase engine power by 
other means on operating engines to achieve scheduled thrust or power 
increases and furnish flight deck information on system operation.
    2. ATTCS. The engine power control system that automatically resets 
the power or thrust on the operating engine (following engine failure 
during the approach for landing) must comply with the following 
requirements stated in paragraphs 2a, 2b, and 2c:
    a. Performance and System Reliability Requirements. The probability 
analysis must include consideration of ATTCS failure occurring after 
the time at which the flightcrew last verifies that the

[[Page 14157]]

ATTCS is in a condition to operate until the beginning of the critical 
time interval.
    b. Thrust or Power Setting.
    (1) The initial thrust or power setting on each engine at the 
beginning of the takeoff roll or go-around may not be less than any of 
the following:
    (i) That required to permit normal operation of all safety-related 
systems and equipment dependent upon engine thrust or power lever 
position; or
    (ii) That shown to be free of hazardous engine response 
characteristics and not to result in any unsafe aircraft operating or 
handling characteristics when thrust or power is increased from the 
initial takeoff or go-around thrust or power to the maximum approved 
takeoff thrust or power.
    (2) For approval of an ATTCS system for go-around, the thrust or 
power setting procedure for the operating engine(s) must be the same 
for go-arounds initiated with all engines operating as for go-arounds 
initiated with one-engine-inoperative.
    c. Powerplant Controls. In addition to the requirements of Sec.  
25.1141, no single failure or malfunction, or probable combination 
thereof, of the ATTCS, including associated systems, may cause the 
failure of any powerplant function necessary for safety. The ATTCS must 
be designed to:
    (1) Apply thrust or power on the operating engine(s), following any 
one engine failure during takeoff or go-around, to achieve the maximum 
approved takeoff thrust or power without exceeding engine operating 
limits; and
    (2) Provide a means to verify to the flightcrew before takeoff and 
before beginning an approach for landing that the ATTCS is in a 
condition to operate.
    3. Critical Time Interval. (Refer to figure 1 and figure 2 below.) 
The definition of the critical time interval in part 25 appendix 
I25.2(b) shall be expanded to include the following:
    a. When conducting an approach for landing using ATTCS, the 
critical time interval is defined as follows:
    (1) The critical time interval begins at point A on a 2.5 degree 
approach glide path. (Point A is the point on that glide path from 
which, assuming a simultaneous engine and ATTCS failure, the resulting 
approach climb flight path intersects, at point B, a flight path 
originating at a later point on the same approach path corresponding to 
the part 25 one-engine-inoperative approach climb gradient.) The period 
of time, time interval AB, must be no shorter than the time in figure 
2, I25.2(b) time interval FG. Figure 2 is reproduced from appendix I 
and includes a change that identifies the time interval FG.
    (2) The critical time interval ends at point D on a minimum 
performance, all-engines-operating go-around flight path from which, 
assuming a simultaneous engine and ATTCS failure, the resulting minimum 
approach climb flight path intersects the flight path (point E) 
corresponding to the 14 CFR part 25 minimum one-engine-inoperative 
approach climb gradient represented in figure 1 as the engine failed, 
ATTCS operating flight path.
    The all-engines-operating go-around flight path and the 14 CFR part 
25 one-engine-inoperative approach climb gradient flight path (engine 
failed, ATTCS operating flight path in figure 1) originate from a 
common point, point C, on a 2.5 degree approach path. The period of 
time, time interval DE, from the point of simultaneous engine and ATTCS 
failure, point D, to the intersection of these flight paths, point E, 
must be no shorter than the corresponding time in figure 2, I25.2(b) 
interval FG.
    b. The critical time interval must be determined at the altitude 
resulting in the longest critical time interval for which one-engine-
inoperative approach climb performance data are presented in the 
airplane flight manual.
    c. The critical time interval is illustrated in figure 1.
    [GRAPHIC] [TIFF OMITTED] TR05MR13.012
    

[[Page 14158]]


[GRAPHIC] [TIFF OMITTED] TR05MR13.013


    Note: Figure 2 is included for reference and clarity to show 
time interval FG. It has not been included in previous special 
conditions on the same subject and does not include any new 
requirements. It does not change the meaning or intent of the 
special conditions.


    Issued in Renton, Washington, on February 13, 2013.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-05006 Filed 3-4-13; 8:45 am]
BILLING CODE 4910-13-P